I made the function which will return me an array with all unprovided informations from user, but I can't get it to work with first element in array.
This is the data which is used as parameter in function:
$data = array(
  $_POST["firstName"] => "first name",
  $_POST["lastName"] => "last name"
);
print_r(return_not_provided($data));
This is the function:
function return_not_provided($formFields) {
    $notProvidedFields = array();
    foreach ($formFields as $field => $value) {
        if (!isset($field) || empty($field))
            array_push($notProvidedFields, $value);
    }
    return $notProvidedFields;
}
And it returns this:
Array ( [0] => last name )
Script notifies me that both indexes are undefined (firstName and lastName) but doesn't push them both in array.
